Inflatable structures are well known in the art. Such known inflatable structures are typically thermoformed of a single type of material. Thermoforming involves heating polymer sheets until they are softened, stretching the sheets over a mold, and holding the sheets in the mold until the sheets become rigid. The desired part is then trimmed from the surrounding web. Exemplary inflatable structures include exercise platforms that are used to improve an individual's balance, and bladders for use in shoewear.
Known inflatable exercise platforms are inflatable disks formed of a single material. Such devices are limiting in that the resistance provided on both sides of the disk, and, therefore, the degree of difficulty, is the same. In use, the user stands on the disk and tries to maintain a stable position, thereby improving the balance, coordination and reflexes of the user.
It is an object of the present invention to provide an inflatable structure formed of dissimilar materials that reduces or overcomes some or all of the difficulties inherent in prior known devices. Particular objects and advantages of the invention will be apparent to those skilled in the art, that is, those who are knowledgeable or experienced in this field of technology, in view of the following disclosure of the invention and detailed description of certain preferred embodiments.